Brake



June 22, 1937.7 w TATTER 2,084,416

BRAKE Original Filed April 3, 1930 2 Sheets-Sheet l INVENTOR ATTORNEYJune 22, 1937.

J. W. TATTER BRAKE Original Filed April 5, 1930 2 Sheets-Sheet 2INVENTOR.

Jay/v W. 74772,?

ATTORNEY.

Patented- June 22, .1937. J

' umrao 1srAras abacus BRAKE JolurW. fatten Akron. oluo. asllgn'ortoBendix Products Corporation, South Bend, Ind a cor poratlon of IndianaRefiled for abandoned applicatloncscrial .No..

441,189, April 3, 1930. This application June 19, 1936, Serial No.86,065

17 Claims. (01. so-54.6)

This is a reflle of my abandoned application Serial No. 441,189, filedApril 3, 1930., My invention relates to brakes and more particularly toa master cylinder-structure adapted 5 for use with a fluid brake systemfor vehicles and the like.

Difliculty has been experienced in maintaining the proper clearancebetween the brake drum and the brake shoe or shoes of a fluid pressure10 actuated brake system due to the tendency toward variations in volumeresulting from temperature variations and also due to wear of thefriction braking elements. Frequent adjustments are found necessary, andin many cases such ad 15 justments are not made as often as requiredresulting in a loss of braking efliciency.

It is the object of my invention to overcome the aforesaid difficultiesand to maintain the braking efficiency of a fluid pressure actuated gobraking system at a maximum atall times by providing means formaintaining substantially the same clearance between the frictionelements irrespective of temperature variations to which the brake fluidis subjected.

25 Another object of my invention is to maintain approximately aconstant clearance between the friction elements of a fluid pressureactuated braking system by maintaining a constant initial fluid pressurein the brake system.

so A further object of my invention is to facilitate the maintenance ofa constant initial fluid pressure in the brake system by providing anadjustable valve that automatically maintains a predeter mined initialfluid pressure in the system irre- 35 spective of temperature variationseffecting the fluid contained in the said brake system.

A still further object of my invention is to provide a more eflicientand'reliable fluid pressure generating device for use with a fluid brakesys- 40 tem by providing valve means for opening or closing acommunicating passage between the reservoir and fluid chamber in advanceof the piston, said valve means being actuated to open the passage whilethe piston is at rest or in an 45 inoperative position to insure anadequate'supply of brake fluid at all times for use in the brake system.

A still further object of my invention is to facilitate the installationand maintenance of a hydraulic brake system by providing easily actuatedmeans permitting the escape of air from the system on iillingthe samewith thebrake fluid.

For a more detailed understanding of my in- 55 vention reference may behad to the accompanying drawings which illustrate one form which myinvention may assume, and in which:

Figure 1 is a vertical sectional view of a master cylinder for a fluidbrake system constructed in accordance with my invention,

Figs. 2, 3, and 4 are detail sectional vie taken respectively on thelines 2-2, 3-3, and

4-4 of Fig. 1, v

Fig. 5 is a detail sectional view taken.substantially on the line 4-4but showing the pipe flttings to which the fluid conduits are connectedremoved,

v ,Fig. 6 is a detail perspective view of the valve for controlling thereturn flow of the fluid.

Fig. '7 is a detail perspective view of the check valve interposedintermediate the fluid chamber and the fluid brake system,

Fig. 8 is a diagrammatic planview of a vehicle showing a fluid brakesystem assembled therewith, and

Fig. 9 is a detail view of the braking mechanism.

My improved master cylinder structure and fluid control mechanism isadapted to be associated with a vehicle such as an automobile or thelike. The chassis frame of the vehicle is designated by the referencecharacter I and supports the front and rear axles II and i2respectively, with which are respectively assembled the front and rearwheels l3 and I4. Fluid pressure actuated brake mechanisms l areassembled to all four wheels and each comprises a brake drum l6 securedto the wheel, an expandingbrake shoe I! being assembled with each brakeband. The brake shoe is expanded by a fluid pressure actuated device l8,the tension springs l9 serving to return the shoe to an inoperativeposition. The devices l8 associated with the front wheels areoperatively connected with a fluid conduit 20, while the devices l8associated with the rear wheels are operatively-connected with a fluidconduit 2 I. v

A master cylinder A comprising upper and lower castings 22 and 23respectively secured together isassociated with this fluid system and isso actuated as to increase the fluid pressure in the system forexpanding the brake shoes to set the brakes. A reservoir 24 isconstructed in the upper master cylinder casting and is provided with anopening 25 adapted for registration with an opening 26 inthe lowercasting 23. An' expansible cup-shaped member 21 is assembled with themaster cylinder structure A, said cup being preferably constructed ofrubber and provided with a circumferential flange 28 about the rimperandlowercastin gs.

Thelow ,eastingflispsovidedwithaeylin- 'dricalchamberorcylinderIlinw'hiehapiston.

mthembbercupsllbeingclampedbetweenthetwopistonpartatowitzthecuptlandthehead si. Thestem llisprovldedwith'aholeu e'xtending longitudinally which isadaptedtoreceivethestemllotavalvefl. usbottornialceoithepisionheadisrecel'edasat' II, thebottom oi the recess providedpreferably with a rubber washer 3| forming a seat ior the valve. Thehole or bore winger in diameter thanthevalvestem flsothatwhenthevalve a0isunseatedthefluidchamber flisinopen communication with the reservoir24, the stud a provided with a hole 8| opening into the interior oithecup I. and the interior of the cup is in open communication with theIt. Pret- 25 erably ahole an constructed in the wallet the cup which isadapted toregister with a hole 4i -i'ormedin theguidewallflcarriedbytheupper casting 22 when thepiston is at rest,thehole ll communicating'with interior of the reservoir-8oadjacentthebottom."lhemckerarmuhaving yoke arms 14 isrotatably'supported by the upper casting 22, the yoke arms beingtoengagethestudttsecuredtothepistonso that when the operator steps onthe brake 88 ll theplston is depressed, the rockarm' and piston beingreturned to an inoperative position when thepressure on the brake pedalis released. The valve It is arranged to be'unseated when the piston isin an inoperative position and this is so accomplished by providing spin4. that is slid- 'ablysupportedbythestudandwhichisadapted to engage anadjustable stop land the end oithe valve stem 8'. As shown'in l 'lg. 1the-valve is unseated establishing a communication beis tween the fluidchamber as and the reservoir u action 01' a light spring llrwhiehabutsthe ad -v Ju'stablescrew ll permitting this pressure to betransmitted to the fluid in the brake system, the increased fluidpressure in the systemactuating so the brake mechanism to coast thebrake shoes with the brake drums. When the brakep edal ll is released,the piston is moved back'to a position of rest corresponding to thatshown in Fig. 1, thepressure oi the fluid in the system closing 05 thecheck valve 49 and opening the return valve II. The opening of thereturn valve 0 is resisted by a manually adjusted spring II, this.spring being secured or attached to a shait I! which may be in thisinstance turned to wind or 7 unwind the spring II to produce more orless resistance to the opening 01' the valve II. An suitable lockingmeans It may be employed to set the shaft 52 in any adjusted position.The purpose oi the valve II and the adiustablemeans 7s tor-resisting theopening or the valve is to mainmovedgafter which the lihlgbrakesystemi'ormaintainingthepsopsrciear- Astheahomand the-brake system,and thus a proper clearance between brake elements is maintained irre-ispectiveoitemperaturevariationsthateflecttheze'rhelowermastereylindercastingllisprovided withasecondfluidchamberlt'thevalves llandllinterposedbetweenthechamberfland abeingsecuredtotheimionsllthatarethreaded intothe'internallythreadedopenings llinthe casting. A flexible diaphragm orvalve ll, as

describedand'claimedinmycopendingspplicaso 2| or llwhena break occurs inone-o! them. An air vent It is provided ior permittirw -the escape 0!air orotherforeign fluids the system',said ventharansedtoblock'the'airvent. closestheair tb whenwi v fluidsinimthesystemtheplugisremovedand a pipe 0 threaded hole. When-theair'crotherfluidhasescapedthevalvemay-beclosedandthepipere- AlthoughIhave illustratedtormolmy." invention and have described in detail but single applicationthereoi it will' those skilled in the art to whichmy inventionivariousmodiflcations and changesmaybemade'thereinwithoutdepartingiromthe spirit oimyinvention orirom thescope-o! the u appended claims. 7 Q

What I claim as my invention is:

positionatalltimes,saidvalveineansbeinglocatedinthemainpressureconduitoi'thebrakesystem, and meansior adiustingsaid resiliently.actuatedvalvemeanstovarytheinitialfluid pressure.

2. Inaflmdbrakesystemprovidedwithh'ake mechanism, the combination ofmeans for desecured-to theenlargedinternslly ates, valve means forcontrolling the return flow oi the fluid from the system through thepassage leading from the bore in which the piston oper-- ates, anadjusting member,'means yieldingly re-' sisting the opening oi saidvalve means to maintain an initial fluid pressure in the brake system,said last mentioned means being suitably anchored to said adjustingmember, and means for locking said adjustable member in its adjustedposition.

4. In a fluid brake system, the combination of means for applyingpressure to the fluid in the brake system, said means comprising a fluidchamber, valve means for controllingthe return flow oi the fluid fromthe system to said fluid chamber, resilient means resisting the openingof said valve means to maintain an initial fluid '30 pressure in saidbrake system, and manually operable means for adjusting the resilientmeans to vary said initial pressure.

5. In a fluid brake system, the: combination of means for applyingpressure to the fluid in the brake system, said means comprisinga fluidreservoir together with a fluid chamber, a piston operating in the fluidchamber of said means, means connecting the fluid chamber of said flrstmentioned means with the fluid brake system, a check valve permittingthe fluid to freely flow from the fluid chamber of said first mentionedmeans to the brake system, means for actuating the piston, valve meansfor controlling the return flow of the fluid from the brake system tothe fluid chamber of said first mentioned means, means yieldinglyresisting the opening of said valve means, and manually operable meansfor adjusting said last mentioned means to maintain any desired initialfluid pressure in the brake system within the limits of said meansyieldingly resisting the opening .of said valve means. I

6. In a fluid brake system, the combination of a friction member, amember adapted to be engaged by said friction member,v means forapplying pressure to the fluid in the brake system to cause saidfriction member to engage said second mentioned member, said meanscomprising a fluid reservoir, a fluid chamber, a piston operating in thefluid chamber, together with means placing the fluid chamber incommunication with the reservoir whenthe'piston is in an inoperativeposition, said last mentioned means extending through the piston, and amanually adjustable valve means intermediate the fluid chamber and-thefluid brake system for selectively maintaining any desired initial fluidpressure. within the limits of said valve means, for maintaining saidfriction member in approximately the same clearance position at alltimes relative to said second mentioned member.

7. A master cylinder for fluid brake systems comprising a casingstructure having a reservoir portion, a cylinder having an end portion,a piston operable in said cylinder, said piston being 75 disposedintermediate the end portion of said cylinder and the reservoir portionof said casing, conduit means in said piston connecting the reservo'irportion of said casing withthe end portion of 7 said cylinder, valvemeans carried by said piston for controlling the flow oi fluid throughsaid conduit means, and means actuating said valve means to unseat thesame while said piston is in an inoperative position. v 8. A mastercylinder for afluld brake syste comprising a casing structure having areservoir portion, a cylinder having an end portion, a piston operablein said cylinder, said piston being disposed intermediate the endportion of said cylinder and the reservoir portion of said casing,

conduit means in said piston, said conduit means connecting thereservoirof said casing with the \end portion of said cylinder,'a valve carriedby said piston for controlling the flow of fluid through said conduitmeans, yielding means for seating said valve, said'yieldin'g means beingcarried by said piston, and means for unseating said valve while saidpiston is in an position. v I v v 9. A master cylinder for a fluid brakesystem comprising a casingstructure having a reservoir portion,acylinder having a piston clearance portion, a piston operable in saidcylinder, said piston being disposed intermediate the reservoir portionof said casing structure and the piston clearance portion oi! saidcylinder, conduit means connectinoperative ing the reservoir portion ofsaid casing structure with the piston clearance portionof said cylinder,said conduit means extending through said piston, valve means forcontrolling the flow 01 fluid through said conduit means, and means forunseating said valve means while the piston is in an inoperativeposition. I

10. A master cylinder for a fluid brake system comprising a casingstructure having a reservoir portion, a cylinder having a. pistonclearance portion, a piston operable in, said cylinder, said pistonbeing disposed intermediate the piston clearance portion of said pistonand the reservoir portion of said casing structure, conduit meansconnecting the reservoir portion of said casing srtucture and the pistonclearance portion of said cylinder, said conduit means extending throughsaid piston, a valve controlling the flow of liquid through said conduitmeans, said valve being provided with a portion extending through saidpiston and projecting into the reservoir portion oi. said casingstructure, and an adjustable memher supported by said casing structure,said adjustable member being adapted to unseat said valve while saidpiston is in an inoperative position.g--

11. In a fluid brake system, the combination 'of a ,fluid chamberconnected with the brake system, said fluid chamber being provided witha valve member suitably mounted therein, said fluid chamber beingfurther provided with a vent pasof said vent passage, said lastmentioned memberhaving an axis extending parallel with the iongitudinalcenter of said vent passage.

12. In a fluid brake system, the combination of a fluid chamberconnected with the brake system,

said fluid chamber being provided with a vent' passage leadingthereirom, a second passage extending'at an angle with and intersectingsaid aoeasio 'tion of varying cross sectional mat the intersection withsaid vent passage. an adjustable member suitably mounted in said secondpassage,

said adJustable member having a portion 01 varying cross sectioniorclosely contacting said portion oi varying cross section oi saidsecond passage at the intersection with said vent passage, and a memberfor passage.

13. In a fluid the combination of a casing having a cylinder,a pistonoper'atively mounted in said cylinder to develop pressuretobetransmittedto-the fluid inthe system, a

fluid chamberiormedbetweenapairoi'opposite- 1y disposed union memberssuitably mounted in said casing and each providedwith passages forconnecting with the fluid brake system,a'-valve member for closing'thepassageoi' one of said union members, a vent passage connecting saidfluid chamber with the atmosphere, a member-tor intersecting and closingsaid vent passage. and;

a member for closing the atmosphere end or said vent passage.

14,111 a fluid brake system having a mmechanism and means forapplyingipressure to the fluid in thesyste'm for actuating the brakemechanism to its engaged position, said means comprising a pistontogether with conduit means for conducting the fluid under pressuredeveloped by said piston to said brake'mechanism meanstormaintaininganinitialflmdpressureinthe "-system, said meansbeing-manualiyadiustableto vary theinitial pressure to compensateiorwear in the brake mechanism, said means being 1 located in said conduitmeans of said flrst mentioned means. a

15. In a fluid brake system. having a brake mechanism. the combinationoi means for applyclos'ing the end oi "said vent tween said pair ofoutletsia mud iromtsaid cylinder to said'valve chamber. asecsuredevelopedbyllldmtolidbrakemeohanism; and means for maintaining aninitial fluid pressureintbebrakesystermsaidlastrneritionedi mm ually mavary m initial pressm'eto compensate vtor' vmar in the mentionedmeans-being located in saidomduit means- .0! said flri mentioned means.I

16. In a fluid brake together witha cylindercyiinderotsaidcasingstmetureandvalvemeans extendingthrough saidriston.'saidvalvemeans providing communication between the reservoirportion and the piston clearance portionoisaidcasingstructurewbenmidpistonisinaninoperative position. V

17. Inamastercylindertcrafluidbrakesystem, the combinationo! acasingstructurep'ovided with a cylinder. a piston operating insaidcylinder, a valve chamber provided with a pair of outlets, valvemeansin said valve chamber beond fluid passage connecting saidvalvechamber and said flrst mentioned fluid passage at a point removedi'romsaid cylinder. valve means permittingfluidr to freely flow from saidcylinder through one oisaid fluid passages to the brake passageleadingsystem,andvalvemeansiorcontrollingtbsre--turnflowoifluidtbroughoneoi'saidpassages to said cylinder. r,

' JOHN W. 'IA'I'I'IR.

7 system, the combination of a casing structure having a reservoirportion} having a'piston clear,-: ance portion, a piston intermediatethe portion and the piston clearanceportiono! the

